This title appears in the Scientific Report :
2014
A Novel Mechanism for Ensuring the Ohmicity of Contacts to n-InP & n-GaAsover a Wide Range of Temperatures down to Helium One: Experiment and Theory
A Novel Mechanism for Ensuring the Ohmicity of Contacts to n-InP & n-GaAsover a Wide Range of Temperatures down to Helium One: Experiment and Theory
At present two physical mechanisms that ensure realization of ohmic contacts to semiconductorsare known [1S.M.Sze]. These are: 1) field emission in presence of a doping step that leads toformation of a strongly degenerate layer in the near-contact semiconductor region and 2) thecase of Schottky cont...
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Personal Name(s): | Sachenko, A. |
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Belyaev, A / Boltovets, N / Vitusevich, Svetlana (Corresponding Author) / Konakova, R / Novitskii, S / Sheremet, V | |
Contributing Institute: |
JARA-FIT; JARA-FIT Bioelektronik; PGI-8 |
Published in: | 2014 |
Imprint: |
2014
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Conference: | The 32nd International Conference on the Physics of Semiconductors, Austin (USA), 2014-08-10 - 2014-08-15 |
Document Type: |
Poster |
Research Program: |
Sensorics and bioinspired systems |
Publikationsportal JuSER |
At present two physical mechanisms that ensure realization of ohmic contacts to semiconductorsare known [1S.M.Sze]. These are: 1) field emission in presence of a doping step that leads toformation of a strongly degenerate layer in the near-contact semiconductor region and 2) thecase of Schottky contacts with low barrier height, below 25 mV.Here we present the results of investigation of temperature dependence of contact resistivity forn-InP- and n-GaAs-based contacts with high dislocation density, performed over a wide range oftemperatures down to helium one. We revealed that the above contacts are ohmic over the wholetemperature range. The results obtained are explained using a novel mechanism of current flow inmetal-semiconductor contacts that differs from those described in [1]. A new mechanism isrelated to the current flow through nano-sized metal shunts associated with dislocations. Becauseof very strong electric fields appearing at the shunt ends adjacent to semiconductor, a highmirror-image potential is realized that reverses sign of band bending in the semiconductor regionsadjacent to the metal shunts. As a result, accumulation band bending is realized in those regions,and the contacts remain ohmic at any temperature.The experimental temperature dependence of contact resistivity curves are nonmonotonic andare in good quantitative agreement with those described theoretically using a new mechanism ofcurrent flow with additional allowance for electron freeze-out at low temperatures. |